This paper presents and discusses the design and implementation of an open source Python programming framework for research and education in power system modeling and simulation. The framework, named the Power System Oscillations Analyzer (PSOA), focuses particularly on providing the basic requirements to encourage rapid development of custom models and simulation software. The framework includes a custom modeling API to create power system models in an intuitive manner and a fully functional GUI for interaction with model data and the framework. Test results are also provided that demonstrate the capabilities of the framework in the analysis of the one machine infinite bus system.